/Engine/Source/Runtime/OpenGLDrv/Public/OpenGLDrv.h
virtual void RHIDrawIndexedIndirect ( [FRHIBuffer](API\Runtime\RHI\FRHIBuffer) * IndexBufferRHI, [FRHIBuffer](API\Runtime\RHI\FRHIBuffer) * ArgumentsBufferRHI, int32 DrawArgumentsIndex, uint32 NumInstances )